This sexy weight range came from a study by MJ Tovee funded by Newcastle University.

In this study, thirty female undergraduates rated color pictures of 50 men in front view. Waist to chest ratio (WCR)—a measure of upper body shape, waist to hip ratio (WHR)—a measure of lower body shape, and BMI were measured for each man. Images were presented in random order with each subject’s head and body obscured.

Results showed that individually all three characteristics were contributors to attractiveness. However, WCR was the principal determinant of attractiveness, accounting for 56 percent of the variance, whereas BMI accounted for only 12.7 percent of the additional variance. WHR was not a significant predictor of attractiveness.

What this means in laymen terms is that the waist to chest ratio was a significant determinant of attractiveness. Its based on the golden ratio which I have explained in this post.

This also proves that fact that our very own Hercules a.k.a Steves Reeves was the most admired bodybuilder of the 20th Century,( even though he will well outside the sexy weight range—215lbs (97kg); height: 185 cm) as he has an awesome WCR (his chest was 49in and waist only a mere 29in)!